[src/trunk]: src/sys/netinet Undo previous backout: alignment is needed here.

[martin <martin%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/482a002d505b
branches:  trunk
changeset: 1018758:482a002d505b
user:      martin <martin%NetBSD.org@localhost>
date:      Tue Feb 16 05:44:13 2021 +0000

description:
Undo previous backout: alignment is needed here.
The reason for the previous backout was a misunderstanding (POINTER_ALIGNED_P
was broken, but the assertion fired even after it got fixed).

diffstat:

 sys/netinet/if_arp.c |  11 +++++------
 1 files changed, 5 insertions(+), 6 deletions(-)

diffs (32 lines):

diff -r 7a79b1df3213 -r 482a002d505b sys/netinet/if_arp.c
--- a/sys/netinet/if_arp.c      Tue Feb 16 05:11:26 2021 +0000
+++ b/sys/netinet/if_arp.c      Tue Feb 16 05:44:13 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_arp.c,v 1.304 2021/02/15 19:49:17 christos Exp $    */
+/*     $NetBSD: if_arp.c,v 1.305 2021/02/16 05:44:13 martin Exp $      */
 
 /*
  * Copyright (c) 1998, 2000, 2008 The NetBSD Foundation, Inc.
@@ -68,7 +68,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.304 2021/02/15 19:49:17 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.305 2021/02/16 05:44:13 martin Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ddb.h"
@@ -707,10 +707,9 @@
                MCLAIM(m, &arpdomain.dom_mowner);
                ARP_STATINC(ARP_STAT_RCVTOTAL);
 
-               if (__predict_false(m->m_len < sizeof(*ar))) {
-                       if ((m = m_pullup(m, sizeof(*ar))) == NULL)
-                               goto badlen;
-               }
+               if (m_get_aligned_hdr(&m, ARP_HDR_ALIGNMENT, sizeof(*ar),
+                   false) != 0)
+                       goto badlen;
                ar = mtod(m, struct arphdr *);
                KASSERT(POINTER_ALIGNED_P(ar, ARP_HDR_ALIGNMENT));